There are known different means for dispersal, by military or police units, of persons illegally gathered. Among these means are live ammunition, water cannon, tear gas and rubber bullets.
As it is usually an aim to disperse such gatherings and subsequently to arrest some or all of the persons involved, none of the above-listed means is effective. The use of live ammunition may cause serious injury and sometimes fatalities. The use of water cannon, tear gas and rubber bullets is effective in causing dispersal of illegal gatherings, and usually causes a minimum of injuries, but subsequent identification of involved persons is very difficult, especially when disguises, such as face-coverings, are worn by them.
A further method used for dispersal of persons illegally gathered, and which also facilitates subsequent identification of the persons involved is the use of water cannon in which the liquid directed at the persons includes a color dye. A disadvantage of using this type of water cannon is that it is difficult to direct the water cannon at only a few persons wanted for detention and who are mixed in with a large crowd of persons without spraying at least a few persons in the crowd who are not required for detention.
In the area of military training, it is often useful to carry out gunfight simulations. When live ammunition is not, however, used, due to the wish to avoid casualties among the participants in such simulations, and "blanks" are used instead, the usefulness of the simulations may be limited. It is appreciated that a way to determine gunfire accuracy is to observe the number and location of the hits scored. When blanks are used, such observation is not possible.